package net.za.cair.dip;

import java.util.HashSet;
import java.util.Set;

import org.semanticweb.owlapi.apibinding.OWLManager;
import org.semanticweb.owlapi.model.OWLAxiom;
import org.semanticweb.owlapi.model.OWLClassExpression;
import org.semanticweb.owlapi.model.OWLOntology;
import org.semanticweb.owlapi.model.OWLOntologyCreationException;
import org.semanticweb.owlapi.model.OWLOntologyManager;
import org.semanticweb.owlapi.model.OWLSubClassOfAxiom;
import org.semanticweb.owlapi.reasoner.OWLReasoner;
import org.semanticweb.owlapi.reasoner.OWLReasonerFactory;

import net.za.cair.dip.model.OntologyStructure;
import net.za.cair.dip.model.Query;
import net.za.cair.dip.model.ReasoningType;
import net.za.cair.dip.util.AxiomManipulator;

/*
 * Copyright (C) 2011, Centre for Artificial Intelligence Research
 *
 * Modifications to the initial code base are copyright of their
 * respective authors, or their employers as appropriate.  Authorship
 * of the modifications may be determined from the ChangeLog placed at
 * the end of this file.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.

 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.

 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */

/**
 * Author: Kody Moodley<br>
 * Centre for Artificial Intelligence Research<br>
 * UKZN and CSIR<br>
 * Date: 10-Oct-2011<br><br>
 */

public class DefeasibleInferenceComputer {
	
	private OWLReasonerFactory reasonerFactory;
	private OntologyStructure ontology;
	
	public DefeasibleInferenceComputer(OWLReasonerFactory reasonerFactory, OntologyStructure ontology){
		this.reasonerFactory = reasonerFactory;
		this.ontology = ontology;
	}
	
	public boolean isEntailed(Query query) throws OWLOntologyCreationException{
		if (query.isTBoxQuery){
			
			/*** TBOX QUERY ***/
			
			if (!query.algorithm.equals(ReasoningType.PREFERENTIAL)){
				
				/*** NON-PREFERENTIAL ***/
				
				Set<OWLAxiom> backgroundKnwldge = new HashSet<OWLAxiom>();
				backgroundKnwldge.addAll(ontology.bBox.getAxioms());
				backgroundKnwldge.addAll(ontology.sBox.getAxioms());
			
				OWLOntologyManager ontologyManager = OWLManager.createOWLOntologyManager();
				OWLOntology tmpOntology = ontologyManager.createOntology(backgroundKnwldge);
			
				OWLReasoner reasoner = this.reasonerFactory.createReasoner(tmpOntology);
			
				/***Find strongest default s.t. antecedent is satisfiable ***/
				int i = 0;
				OWLClassExpression newConsequent = OWLManager.getOWLDataFactory().getOWLObjectComplementOf(query.antecedent);
				OWLClassExpression strongestDefault = query.ranking.getDefaultClassExpression(i);
				OWLSubClassOfAxiom maxiSatisfiableQuery = OWLManager.getOWLDataFactory().getOWLSubClassOfAxiom(strongestDefault, newConsequent);
			
				while (reasoner.isEntailed(maxiSatisfiableQuery)){
					i++;
					strongestDefault = query.ranking.getDefaultClassExpression(i);
					maxiSatisfiableQuery = OWLManager.getOWLDataFactory().getOWLSubClassOfAxiom(strongestDefault, newConsequent);
				}
			
				OWLSubClassOfAxiom fullQuery = OWLManager.getOWLDataFactory().getOWLSubClassOfAxiom(OWLManager.getOWLDataFactory().getOWLObjectIntersectionOf(query.antecedent, strongestDefault), query.consequent);

				return reasoner.isEntailed(fullQuery);
			}
			else{
				
				/*** PREFERENTIAL ***/
				
				OWLAxiom axiom = AxiomManipulator.getPreferentialQueryAxiom(query.originalAxiom);
				OWLSubClassOfAxiom sub = (OWLSubClassOfAxiom)axiom;
				
				Set<OWLAxiom> backgroundKnwldge = new HashSet<OWLAxiom>();
				backgroundKnwldge.addAll(ontology.bBox.getAxioms());
				backgroundKnwldge.addAll(ontology.sBox.getAxioms());
			
				OWLOntologyManager ontologyManager = OWLManager.createOWLOntologyManager();
				OWLOntology tmpOntology = ontologyManager.createOntology(backgroundKnwldge);
			
				OWLReasoner reasoner = this.reasonerFactory.createNonBufferingReasoner(tmpOntology);
			
				/*** Find strongest default s.t. antecedent is satisfiable ***/
				int i = 0;
				OWLClassExpression newConsequent = OWLManager.getOWLDataFactory().getOWLObjectComplementOf(sub.getSubClass());
				OWLClassExpression strongestDefault = query.ranking.getDefaultClassExpression(i);
				OWLSubClassOfAxiom maxiSatisfiableQuery = OWLManager.getOWLDataFactory().getOWLSubClassOfAxiom(strongestDefault, newConsequent);
			
				while (reasoner.isEntailed(maxiSatisfiableQuery)){
					i++;
					strongestDefault = query.ranking.getDefaultClassExpression(i);
					maxiSatisfiableQuery = OWLManager.getOWLDataFactory().getOWLSubClassOfAxiom(strongestDefault, newConsequent);
				}
			
				OWLSubClassOfAxiom fullQuery = OWLManager.getOWLDataFactory().getOWLSubClassOfAxiom(OWLManager.getOWLDataFactory().getOWLObjectIntersectionOf(sub.getSubClass(), strongestDefault), sub.getSuperClass());
				
				return reasoner.isEntailed(fullQuery);
			}
			
			/***************************/
			
		}
		else{
			
			/*** ABOX QUERY ***/
			
			ABoxToolBox toolbox = new ABoxToolBox(reasonerFactory, ontology);
			toolbox.prepareABoxResources(query.ranking, ontology.asOWLOntology(), query.individual);
			
			if (toolbox.uniqueABoxExtensionExists){
				System.out.println("UNIQUE EXTENSION");
				OWLOntology ontology = OWLManager.createOWLOntologyManager().createOntology(toolbox.uniqueABoxExtension);
				return reasonerFactory.createReasoner(ontology).isEntailed(query.originalAxiom);
			}
			else{
				System.out.println("MULTIPLE EXTENSION!!!");
				return toolbox.aBoxProcedure(query.ranking, query.originalAxiom, toolbox.individualSequences);
			}
			
			/******************/

		}
		
	}
}
